In homer’s Odyssey, the heroic traveler Odysseus survived a series of challenges through either mental or physical prowess. Acrobatic strength vanquished the Cyclops, but the key to breaching the walls of Troy was a clever gambit—the Trojan horse—rather than direct military assault. And of course, like any hero, Odysseus met every obstacle that Homer threw at him with determination and confidence rather than fear or despair.

Decades of research in gerontology, the study of aging, has found that the qualities that allowed Odysseus to triumph also promote general health and longevity. This counts not just for living longer, but living better: avoiding chronic depression, preserving your memory and other mental skills, and functioning independently in your daily life.

Healthy brain aging
In recent decades, scientists have radically redefined the concept of “healthy brain aging.” The ruling paradigm was once that living to a ripe old age was simply a matter of avoiding chronic disease. As for the brain, it was assumed that it would simply go along with the body for the ride—until gradual, inevitable decay transformed us all into the stereotype of the doddering, forgetful, senile elder.

There was just one problem with this: Many people make it to 100 with their mental powers virtually intact, and lead physically active, interesting, satisfying lives. How did they manage to escape the “inevitable decline” that defined old age in the popular imagination?

The Three Keys
Aging researchers found a way to ask the question. The tool is called a longitudinal aging study. Healthy people would be recruited in youth and then tested periodically throughout life to measure any changes in their physical and mental function as well as their lifestyles: what they ate, how much they exercised, and their leisure and social activities.

One of the most well known longitudinal studies, though not the first, was the MacArthur Study. It tracked healthy people from middle age into their 80s. As part of the project, MacArthur researchers identified 1,200 healthy people between the ages of 70 and 80 whose mental abilities ranked in the top third compared to the general population in this age group. The researchers tracked these high performers for a decade and determined who among them tended to remain high-functioning. They identified three factors that distinguished these people from the others:

• They were more consistently physically active than the others. They took daily walks and other forms of exercise, for example.
  
• They remained mentally active. These are the people who, rather than parking in front of the TV, did the crossword puzzle every morning, browsed the library shelves regularly for new and interesting books, dabbled in hobbies and crafts, or played bridge three times per week.
  
• They had a personality quality some have termed “self-efficacy.” They met challenges with the confidence and desire to solve them, rather than being ground under the wheels of misfortune.

In short, they were like Odysseus. To their brains, they were heroes.

Bulking Up Your Brain
From the MacArthur and other longitudinal studies has come a guiding principle known as “use it or lose it.” A recent brain-scanning study appeared to show this principle in action. As reported in the January 22, 2004 Nature, 23 healthy people, average age 22, learned how to juggle. After three months, MRI scans showed enlargement of the gray matter in their brains—the part responsible for higher mental functions. Either existing cells had grown denser, more numerous connections, or the sheer number of brain cells had increased. When the study participants stopped juggling, their brains shrunk again. This doesn’t mean we should all juggle our way to cognitive vitality. But it does strongly suggest that mental exercise has real and positive effects on brain function.

Dancing Away Dementia?
Some researchers have wondered whether mental activity might reduce the risk of Alzheimer's disease. In a study in the June 19, 2003, New England Journal of Medicine, researchers tracked 469 people aged 75 to 85 for up to 21 years. None had dementia at the start. People who participated the most in leisure activities—including reading, playing board games, playing musical instruments, and dancing—were at 63 percent lower risk of being diagnosed with dementia.

It may be that the active people built up a mental bank account that helped delay the onset of dementia symptoms. “It might provide some reserve,” explains Robert N. Butler, M.D., president and CEO of the International Longevity Center in New York City. “They’ve got enough there that even though there is decay underneath, they are still able to function pretty well.”

However, Dr. Butler, who in the 1950s led the first longitudinal studies of healthy older people, is reluctant to promise that a healthy-aging lifestyle can actually prevent Alzheimer’s. “What I am reasonably sure of is that the various sorts of apparent cognitive impairment in the later years, as well as depression, are influenced by the level of mental activity.”

Fortunately, there are no known health risks to doing crossword puzzles or reading novels. Even if lifelong mental “neurobics” doesn’t prevent dementia, it may support general brain function and enhance your overall quality of life.

Social And Physical Fitness
It should be emphasized that physical fitness is also associated with lower risk of cognitive decline. Longitudinal studies also suggest that remaining socially engaged aids healthy aging. “Those individuals who had goals in life, something to get up for, actually did better and lived longer,” says Butler.

Butler, now in his 70s, ought to know. He has hardly slowed the pace of his career since 1982, when he left his position as the founding director of the National Institute on Aging to found the first department of geriatric medicine in the United States, at Mount Sinai School of Medicine in New York City. Perhaps, like Odysseus, we all need a quest in order to maintain our physical and mental zest.

Further Reading

“Living To 100: Lessons In Living To Your Maximum Potential At Any Age,” by Thomas T. Perls, Margery Hutter Silver, and John F. Lauerman. (Basic Books: 1999. 282 pages, paperback.)
“Keep Your Brain Young,” by Guy McKhann and Marilyn Albert. (John Wiley & Sons, Inc: 2002. 296 pages, paperback.)
“Successful Aging,” John W. Rowe and Robert L. Kahn. (Dell Publishing: 1998. 265 pages, paperback.)
“Achieving And Maintaining Cognitive Vitality With Aging,” by the International Longevity center—USA, Canyon Ranch Health Resort, and the National Institute On Aging. Download for free: www.ilcusa.org/pub/books.htm